Milking machine pulsator



June 4, 1940. w, 2,202,997

MILKING MACHINE PULSATOR Filed April 5, 1939 Hajj. A

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Patented June 4, 1940 UNITED STATES 2,202,997 MILKING :MACHINE PU s 'ron Walter A. Scott, Poughkeepsie, N. Y.,' assignor to The De Laval Separator Company, New York, N. Y., a corporation'of New Jersey Application April 5, 1939, Serial No. 266,068

4 Claims.

My invention relates to milking machine pulsators of the type shown in Patent No. 1,808,- 114 to G. K. W. Johansson, dated June 2, 1931, in which two valves with their axes parallel are operated by a common diaphragm having its center midway between the axes of the two valves.

The object of the invention is to improve the operation of the pulsator. In the patent referred to, connection from the diaphragm to the two valve stems is made by a metal cup each of whose opposite edges enters a notch cut in one side of one of. the valve stems. This, by introducing side pressure and preventing rotation of the valves, causes excessive friction, uneven action and unequal wear of the valves.

I have found that, by substituting for the cup a plate having at its center a slot fitting in a groove around a stem attached to the center of the diaphragm and at right angles thereto two slots fitting in grooves around the valve stems, I can eliminate side pressure, allow rotation of the valves and cause more even wear.

In the accompanying drawing, which illustrates one embodiment of my invention- Fig. 1 is a longitudinal section of a pulsator having two parallel valves, operated through my improved connecting member, by a diaphragm;

Fig. 2 is a bottom view of a diaphragm with a connector attached thereto;

Fig. 3 is a detail view of the end of one of the valve stems; and

Fig. 4 is a detail view of the diaphragm stem.

The construction and operation of the pulsator will first be briefly described without reference to my invention.

In the pulsator casing a is a port V in constant communication with a source of vacuum and with a chamber 0 surrounding the common stem of two valves d and 2 having between them an annular member 1 providing, at opposite ends,

seats for the two valves. A chamber g, in which valve d reciprocates, communicates, through a port 9, with a chamber h, which, through a channel h, communicates with a chamber 1' in communication, through a channel It, with the inflations of a pair of teat cups (not shown).

In the pulsator casing is a port A which is in constant communication with the atmosphere and opens into a chamber 111. in which a valve n reciprocates, this valve being adapted to engage, in one position, a seat 0 at one end of an air chamber s and in its other position toseat against a stationary member p separating chambers i and m. Chamber 8, through a channel It, communicates with the inflations of another set of teat cups.

The stem of valves d and e extends through a nut 15 and ahub thereon. The stem of valve 11 extends through a nut 11 and a hub thereon which carries the member 1). These nuts close the chambers h and i from a chamber w which is separated by a diaphragm '0 from. a chamber w. A port hconnects channel h with chamber w. By means of a plate a), hereinafter more particularly described, diaphragm v is connected to the ends of the two valve stems.

Ports 1?, in member 30 and the hub of nut u, connect chamber m with chamber 2'. Chamber s is in constant communication with compartment to by means of a channel 1!. The flow of air through channel y is controlled by a throttle z.

The operation of the pulsator is substantially the same as that of the pulsator of Patent No. 1,808,114 referred to above, in which the movement of the diaphragm and valve system in either direction brings into action pneumatic forces tending to cause, and eventually causing, movement of the diaphragm and valve system in the opposite direction. 1

Describing now the connection between diaphragm v and the valve stems embodying my improvement: The stem ll of the diaphragm v is provided with an annular groove 12. The plate :0 has a central cross slot l3 by which the plate is loosely fitted in the groove l 2 of the diaphragm stem. The plate a: is provided at its ends with two slots 14 and I5 extending longitudinally thereof and at right angles to the direction of extension of slot l3. Each of the two valve stems l6, I! has around the end thereof an annular groove [8. Slots M and 15 fit loosely in the annular' grooves l8 of the two valve stems.

Theslots l4 and I5 fitting loosely in the groove l8 of the valve stems contact each stem at two diametrically opposite points so as to give a direct axial pressure on the stem. They also allow free rotation of the valves. The slots being in line, allow perfect freedom of movement in one direction, in this case longitudinally of the plate 17, and theslot l3 being at right angles to slots 14 and 15 allows perfect freedom of movement in the other direction so that there is no side pressure on the valve stems in any direction.

From the above it will be understood that I have eliminated all side pressure on the valve,

iii

What I claim and desire to protect by Letters Patent is:

1. In a milking machine pulsator comprising two cylindrical valves and valve stems with their axes parallel, a valve-operating diaphragm in a plane at right angles to the axes of the valves, and a stem on the diaphragm located centrally thereof and midway between said axes, means connecting said diaphragm stem and valve stems for transmitting axial movement from the diaphragm to the valves without side pressure thereon and without creating resistance to rotation of the valves, said means comprising a plate having a central slot straddling the stem on the diaphragm and having end slots, at right angles to the first slot, straddling the stems of the respective valves.

2. In a milking machine pulsator comprising two cylindrical valves and valve stems with their axes parallel, a valve-operating diaphragm in a plane at right angles to the axes of the valves, and a stem on the diaphragm located centrally thereof and midway between said axes, means connecting said diaphragm stem and valve stems for transmitting axial movement from the diaphragm to the valves without side pressure thereon and without creating resistance to rotation of the valves, said means comprising a plate having a central slot extending at right angles to a line connecting the axes of said valve stems and straddling the diaphragm stem and having end slots extending parallel to said line and straddling the stems of the respective valves.

3. In a milking machine pulsator comprising two cylindrical valves and valve stems with their axes parallel, a valve-operating diaphragm in a plane at right angles to the axes of the-valves, and a stem on the diaphragm located centrally thereof and midway between said axes, means connecting said diaphragm stem and valve stems for transmitting axial movement from the diaphragm to the valves without side pressure thereon and without creating resistance to rotation of the valves, said means comprising an annular groove in each stem forming a smaller diameter portion between two larger diameter portions, and a plate having a central slot straddling the small diameter portion of the diaphragm stem and end slots, .at right angles to the first slot, straddling the smaller diameter portions of the respective valve stems.

4. In a milking machine pulsator comprising two cylindrical valves and valve stems with their axes parallel, a valve-operating diaphragm in a plane at right angles to the axes of the valves, and a stem on the diaphragm located centrally thereof and midway between said axes, means connecting said diaphragm stem and valve stems for transmitting axial movement from the diaphragm to the valves without side pressure thereon and without creating resistance to rotation of the valves, said means comprising an annular groove in each stem. forming a smaller diameter portion between two larger diameter portions, and

a plate which extends between the larger diam} eter portions of the diaphragm stem and which,

midway of its length, has a hole of greater area than the smaller diameter portion of the ldi'af phragm stem, said plate also having slots par-' 

